MATEMATYKA wydział Ekonomii UB


X, Y X = " = Y 

X Y  " X Y.


xy '" xz ! y = z.
x"X y"Y z"Y
 x
[x] := {y " Y : xy}
1
a)  " R R  = {(x, y) " R2 : x2 + y2 = 1}
[0] = {-1, 1}
b)  = {(x, y) " R2 : x2 + y2 = 1 '" x 0}

" x " (-", -1) *" (1, +"),
"
[x] =
1 - x2 x " [-1, 1].
f " X Y
(x, y) " f xfy y = f(x)
f " X Y

df
Df = {x " X : y = f(x)}.
y"Y
f " X Y

df
Pf = {y " Y : y = f(x)}.
x"Df
f : X Y f " X Y
Df = X
X Y
f : X Y

f(X) = Y ! y = f(x),
y"Y x"X
 XY XY  " XY
 
X Y  = X Y 
X X = Y
a) f : R R f(x) = sin x x " R
f(Df) = [-1, 1] = R

b) f : R [-1, 1] f(Df) = Y = [-1, 1]
f : X Y

x1 = x2 ! f(x1) = f(x2) ! [f(x1) = f(x2) ! x1 = x2],

x1,x2"X x1,x2"X
ax-a-x
f(x) = x " R a " (0, 1) *" (1, +")
2
1 1 2 2
ax - a-x ax - a-x
f(x1) = f(x2) ! = !
2 2
1 1 2 2 1 2 2 1
ax - a-x = ax - a-x ! ax + a-x = ax + a-x !
1 1-x2 2
1-x2 1 2
ax (1 + a-x ) = ax (1 + a-x ) ! ax = ax .
(x) = ax, x " R, (a " (0, 1) *" (1, ")
x1 = x2
f
f : X Y

1
x = 0,

x
f(x) = R
0 x = 0,
R
f x1, x2 = 0

1 1
f(x1) = f(x2) ! = ! x1 = x2.
x1 x2
f(x1) = f(x2) x1 = 0 x2 = 0 0 = f(x1) =

f(x2) = 0 x1 = x2 = 0 f

f y " R y = 0 y = f(x) !

1 1
y = ! x = y = 0 f(x) = y = 0 x = 0 f
x y
f

x x " Q,
f(x) =
-x x " R \ Q,
R R
f : X Y X Y A " X B " Y
A f

f(A) = {y " Y : y = f(x)}.
x"A
B f

f-1(B) = {x " X : y = f(x)}.
y"B
f(x) = x2, x " R A1 = R, A2 = [0, +"), A3 = N
A4 = Z B1 = (-2, -1) B2 = [1, +") B3 = {n " N : n = k4, k " N}
f(A1) = [0, ") f(A2) = [0, ") f(A3) = {n " N : n = k2, k " N}
f(A4) = {0} *" f(A3) f-1(B1) = " f-1(B2) = (-", 1] *" [1, ") f-1(B3) = Z \ {0}
f : X Y A1, A2 " X B1, B2 " Y
1. f(A1 *" A2) = f(A1) *" f(A2)
2. f(A1 )" A2) " f(A1) )" f(A2)
3. f-1(B1 *" B2) = f-1 *" f-1(B2)
4. f-1(B1 )" B2) = f-1(B1) )" f-1(B2)
2. f(x) = x2, x " R A1 = [-1, 0]
A2 = [0, 1]
f(A1 )" A2) = f({0}) = {0}.
f-1([-1, 0]) = [0, 1] = f-1([0, 1]) ! f-1(A1) )" f-1(A2) = [0, 1].
f-1(A1 )" A2) f-1(A1) )"
f-1(A2)
2.
f : X Y Y
f(X) = Y
f : Df R Df " R f : Df R Df " Rn n " N
f
{(x, y) " R2 : y = f(x)}.
f(x) = ax + b, x " R, (a, b " R).
a b
f(x) = ax2 + bx + c, x " R, (a, b, c " R, a = 0).

n
n

f(x) = akxn-k, x " R, (a0, . . . , an " R, a0 = 0), n " N.

k=0
ax + b d
f(x) = , x " R \ {- }, (a, b, c, d " R, c = 0, ad - bc = 0).

cx + d c
a
y =
c
x = -d f
c
P (x)
f(x) = , x " R \ {x " R : Q(x) = 0},
Q(x)
P Q
f(x) = ax, x " R, (a " (0, 1) *" (1, +")).
R (0, +")
fm(x) = axm, x " Df , (m " R).
m

0
= a0,
k=0 ak n , n = 0, 1, . . . .
n+1
= ak + an+1,
k=0 k=0

ad - bc = 0 A =
a b
Det(A) = ad - bc
c d
Df fm m m = 2 Df = R
m 2
1
m = Df = [0, +")
1/2
2
f(x) = logax, x " (0, +"), (a " (0, 1) *" (1, +")).
f(x) = sin x, x " R.
f(x) = cos x, x " R.
sin x Ą
f(x) = tgx a" , x " R \ {x " R : x = + kĄ, k " Z}.
cos x 2
cos x
f(x) = ctgx a" , x " R \ {x " R : x = kĄ, k " Z}.
sin x
f : Df Y, g : Dg W f(Df) " Dg
h = g ć% f : Df W
df
h(x) = (g ć% f)(x) = g(f(x)), x " Df,
f g
df
x a (logax = b, b " R) ! ab = x
a
logaxp = p logax, p " R logaax = x, x " (0, +") alog x = x, x " R loga(x y) = logax +
logay, x, y > 0
"
f(x) = x2, x " R, g(x) = x, x 0
f : R [0, +") g : [0, +") [0, +") f(R) =
[0, +") = Dg
"
(g ć% f)(x) = g(f(x)) = g(x2) = x2 = |x|, x " R.
g(Dg) = [0, +") " Df = R f ć% g
" "
(f ć% g)(x) = f(g(x)) = f( x) = ( x)2 = x, x " [0, +").
f g
" "
f(x) = -x, x 0 g(x) = x, x " [0, +")
Dg = [0, +") = f(Df) g ć% f

" " "
4
(g ć% f)(x) = g(f(x)) = g( -x) = -x = -x, x " (-", 0].
f ć% g f(Dg) = [0, +") " Df = (-", 0]
f : X Y
g : Y X f

g(y) = x ! f(x) = y.
y"Y
f : X Y
g : Y X

(g ć% f)(x) = x '" (f ć% g)(y) = y.
x"X y"Y
f
g f
f
g (x, f(x))
f y = x, x " R
(g(y), y) y = f(x) x " Df
f(x) = x2, x " (-", 0]
Df = (-", 0] Pf = [0, +")
g : [0, +") (-", 0] f
"
" " "
g(y) = x ! f(x) = y ! x2 = y ! x2 = y ! |x| = y ! x = - y.
x
y g
g : [0, +") (-", 0]
"
x g(x) = - x.
"
(g ć% f)(x) = g(f(x)) = g(x2) = - x2 = -|x| = -(-x) = x, x " (-", 0].
" "
(f ć% g)(x) = f(g(x)) = f(- x) = (- x)2 = x, x " [0, +").
f : Df Y " = D " Df

h = f|D : D Y
x h(x) = f(x)
f D
f : R [-1, 1] f(x) = sin x x " Df = R
D
Ą
Df D = [-Ą , ] h f D
2 2
Ą
h = f|D : [-Ą , ] [-1, 1]
2 2
x h(x) = sin x
Ą
[-Ą , ] [-1, 1] h
2 2
h g h
x " D g(x)
arcsinx x
Ą
arcsin : [-1, 1] [-Ą , ]
2 2
x arcsinx.
Ą Ą
df
(h ć% f)(x) = arcsin(sin x) = x, x " [- , ]
2 2
df
(f ć% h)(x) = sin arcsinx = x, x " [-1, 1].
Ą
f(x) = sin x, x " [-Ą , ]
2 2
arcsin [-1, 1]
Ą
sinus 0,
6
arcsin(0) =
Ą
0, arcsin(1) =
2 6
f
f = cos|[0,Ą] : [0, Ą] [-1, 1]
df
x f(x) = cos x.
f
[0, Ą] [-1, 1] g
f arccos
g = arccos : [-1, 1] [0, Ą]
x arccosx.
Ą
arccos1 = 0, arccos0 =
2
Ą
(") arcsinx + arccosx = , x " [0, 1].
2
Ą
u = arcsinx v = arccosx u, v " [0, ]
2
x = sin u = cos v
Ą
sin u = cos v ! sin u = sin ( - v) !
2
Ą Ą
u = - v + 2kĄ, k " Z (" u = Ą - ( - v) + 2lĄ, l " Z.
2 2
Ą Ą
k = 0 u = - v u + v =
2 2
k = 0

Ą
k = 0 u-v =
2
Ą
u = v = 0 k
2
Ą
u + v = (")
2
Ą
f : (-Ą , ) R
2 2
df
x f(x) = tgx.
Ą Ą
f (-Ą , ) (-Ą , )
2 2 2 2
R g f
arctg
Ą
g = arctg : R (-Ą , )
2 2
x arctgx.
arctg0 = 0, arctgĄ = 1
4
f : (0, Ą) R
df
x f(x) = ctgx.
f (0, Ą) R
g f g = arcctg
g = arcctg : R (0, Ą)
x arcctgx.
Ą Ą
arcctg1 = , arcctg0 =
4 2
A, B, C, . . . , X, Y, Z, . . . a A
" a " A A a a
A
X Y X Y
X Y = {(x, y) : x " X '" y " Y }
(x, y) x X y
Y
 X Y
X Y
X  " X X X
X
d : X [0, +")
X

a) d(x, y) = d(y, x)
x,y"X
b) [d(x, y) = 0 ! x = y]
x,y"X
c) d(x, y) d(x, z) + d(z, y)
x,y,z"X
(X, d)
a = b d(a, b) > 0

X = R d(x, y) = |x - y|, x, y " R
R
d : R R [0, +")
a), b), c) R
x0 " X r > 0
df
K0(x0, r) = {x " X : d(x0, x) < r}.
R K0(x0, r) = (x0 - r, x0 + r)
x0 r > 0
df
K-(x0, r) = {x " X : d(x0, x) r}.
R K-(x0, r) = [x0 - r, x0 + r]
(X, d)
A X

K0(x, r) " A.
x"A
K0(x,r)
R
A X \ A A
X X
R
{x}
A (X, d)
K0(x0, r) X A " K0(x0, r)
A (X, d)

A \ K0(x0, r) = ".

K0(x0,r)"X
f a" (an)n"N : N X
not
n f(n) = an
X
f a1, a2, . . .
(an)n"N (an) an, n " N
(an)
f = (an)n"N  : N N
g = (bn)n"N g = f ć% 
bn = a(n), n " N,
(an)
1 1
R an = , n " N bn = , n " N
n n2
(an)

an-1 n = 2k, k " N,
cn =
an+1 n = 1, 3, . . . , 2k - 1, k " N,
(an)
(X, d)
(an) X
a " X

an " K0(a, ).
no"N n n0
K0(a, )
R

|an - a| < .
>0 n n0
n0"N
a (an) (X, d)
lim an = a (" an n" a
-
n"
n an a an
a n
an = a, n " N limn" an = a
limn" an = a limn" an = b a = b

d(a.b) = > 0


d(an, a) <
2
>0 n n0
n0"N


d(an, b) < .
2
>0 n0 n n0
n max{n0, n0}

0 < = d(a, b) d(a, an) + d(an, b) < + = .
2 2
> 0 <
X = R R
(an)n"N

|an| M.
M"R n"N
R
(an), (xn) (bn) R

10 an xn bn
n0"N n n0
2o limn" an = x limn" bn = x
(xn) limn" xn = x
(xn) (yn) R x y

xn yn,
n0"N n n0
x y
(xn) R

(C) |xn - xn+m| < .
>0 n0"N n n0,m"N
R
R
(an) (bn)
limn"(an ą bn) = limn" an ą limn" bn
limn"(can) = c limn" an c " R
limn" an bn) = (limn" an) (limn" bn)
limn" an
limn" an = limn" bn = 0

bn limn" bn
limn"(an)p = (limn" an)p p " Z \ {0}
"
"
k
k
limn" an = limn" an k " N \ {1}
an x

|an - x| < .
>0 n0"N n n1
bn x

|bn - x| < .
>0 n0"N n Ć
Ć n0
n H0 = max{n0, n0, n0}
Ć
x - < an < xn < bn < x + ,

|xn - x| < ,
n H0
xn x
"
n
limn" = 1
"n
n
limn" a = 1 a > 0
"
n
n 2 n - 1 > 0
" "
n n
n = ( n - 1) + 1
(X, d)

(C) d(xn, xn+m) < .
>0 n0"N n n0,m"N
n

n

"
n
n
n = ( n - 1)k
k
k=0
" " "
n(n - 1)
n n n
n = 1 + n( n - 1) + ( n - 1)2 + . . . + ( n - 1)n .

2
>0 >0
"
n(n - 1)
n
n - 1 > ( n - 1)2
2
"
2
n
( n - 1)2 <
n

"
2
n
1 < n < 1 + ,
n
n 2

"
2
n
an = 1, xn = n, bn = 1 + , n = 2, 3, . . .
n
xn 1
b)
1
an = (1 + )n, n " N.
n
(an)

an+1 > an.
n"N
n
n
(a + b)n = an-kbk a, b " R n " N
k=0 k

n

1 n 1
(1 + )n = ( )k =
n k n
k=0
1 n(n + 1) 1 n(n - 1)(n - 2) 1
1 + n + + + . . .
n 2 n2 1 2 3 n3
n(n - 1) . . . (n - n + 1) 1
+ =
1 2 . . . n nn
1 1 1 1 2
1 + 1 + (1 - ) + (1 - )(1 - ) + . . . +
2! n 3! n n
1 1 n - 1
(1 - ) . . . (1 - ) <
n! n n
1 1 1 1 2
1 + 1 + (1 - ) + (1 - )(1 - ) + . . .
2! n + 1 3! n + 1 n + 1
1 1 n - 1 1 1 2 n
+ (1- ) . . . (1- )+ (1- )(1- ) . . . (1- ) = an+1.
n! n + 1 n + 1 (n + 1)! n + 1 n + 1 n + 1
1 1 1
an = (1 + )n < 1 + 1 + + . . . + <
n 2! n!
1 1 1 1 1 1
2 + + + . . . + = 2 + (1 + + . . . + ) =
2 22 2n-1 2 2 2n
1
1 - (1)n-1
2
2 + < 3.
1
2 1 -
2
e
(an)

an = 0.

n0"N n n0
an+1
lim | | = ą < 1.
n"
an
(an)
z
e (0) (z) = limn"(1 + )n, z " C
n
e H" 2, 71...
(an) " R
(an)
+" -"
ł ł

ł
an > M an < młł .
M"R n0"N n n0 m"R n0"N n n0
0 "
" - " 0 " 1" "0 00
0 "
a) limn" Pk(n) P Q k l
k Ql(n) l
Pk(n) = asnk-s, Ql(n) = brxl-r, x " R.
s=0 r=0
ńł
0 k < l,
ł
ł
ł
a0
ł
Pk(n) k = l
b0
lim =
n" ł
+" k > l '" a0 b0 < 0,
Ql(n)
ł
ł
ół
-" k > l '" a0 b+0 < 0.
b) limn"(7n - 5n - 3n - 1)
n-n2
c) limn" 2n2-1
2n2+1
b) " - "
["-"]
lim (7n - 5n - 3n - 1) = lim [7n - (5n + 3n + 1)] =
n" n"
5n 3n 1
lim 7n[1 - ( + + )] = [" 1] = +".
n"
7 7 7n
c) 1"
1
limn" an = limn"(1 - )n = e-1
n
n > 1
1 n - 1 n (n - 1) + 1
an = (1 - )n = ( )n = ( )-n = ( )-n =
n n n - 1 n - 1
-n
n-1
1 1
(1 + )-n = (1 + )n-1 .
n - 1 n - 1
1
lim an = e-1 = .
n"
e
b)
n-n2
(2n2) + 1) - 2
lim xn = lim =
n" n"
2n21 + 1
n-n2
ł łł
n2 1
1
+
n2+
2
2
1
ł ł
lim 1 - = (e-1)-1 = e.
1
n"
n2 +
2
x0 " R A " R
x0 A
x0 A x0
f : Df R Df " R x0
Df f
f g " R
x0 limxx f(x) = g
0

lim xn = x0 ! lim f(xn) = g.
n" n"
(xn)"Sx0 )"Df
f g " R
x0

x " Sx , ! f(x) " Ug, .
0
Ug, Sx0, x"Df

0 < |x - x0| <  ! |f(x) - g| < .
>0 >0 x"Df
sin x
limx0 f(x) = 1 f(x) =
x
x " R \ {0}
1
1
"AOB sin x
2
x
AOB
2
tgx
"AOC
2
sin x x tgx Ą
, x " (0, ).
2 2 2 2
sin x Ą Ą
cos x 1, x " (- , 0) *" (0, ).
x 2 2
Ą
(xn) " (-Ą , 0) *" (0, n " N limn" xn = 0
2 2
sin xn
cos xn 1, n " N.
xn
limn" f(xn) = 1 (xn)
limx0 sin x = 1
x
f : Df R g : Dg R D = Df )" Dg = "

D, Df, Dg " X (X, d) x0 D
limxx f(x) = a limxx g(x) = b
0 0
1. limxx (f(x) ą g(x) = a ą b
0
2. limxx (f(x)g(x)) = a c
0
a
3. limxx f(x) = b = 0

0
g(x) b
f : Df R Df " R

lim f(x) = g " R ! |f(x) - g| < .
x+"
>0 >0 x>

lim f(x) = g " R ! |f(x) - g| < .
x-"
>0 <0 x<
f : Df R Df " R x0 Df

lim f(x) = +" ! 0 < |x - x0| <  ! f(x) > M.
xx0
M>0 >0 x"Df

lim f(x) = -" ! 0 < |x - x0| <  ! f(x) < m.
xx0
m<0 >0 x"Df
f : Df (Y, ) Df " X (X, d) (Y, ) x0 " Df
f x0

x " Ux ! f(x) " Uf(x ) !
0 0
Uf (x0)"Y Ux0 "X x"Df

d(x, x0) <  ! (x, x0) < .
>0 >0 x"Df
f A " Df
A
f : Df R Df " R
f
A " Df
1o

|f(x) M.
M>0 x"A
2o A
f [a, b] " Df
f([a, b]) = (c, d) c < d

f(x) = .
"(c,d) x"(a,b)
f : A R, A " R
A

|x1 - x2| <  ! (f(x1) - f(x2)| < .
>0 >0 x1,x2"A
a) f(x) = 2x x " R

> 0  =
2

|x1 - x2| <  ! |f(x1) - f(x2)| = |2x1 - 2x2| = 2|x1 - x2| < 2 = .
x1,x2"R
b) f(x) = x2, x " R

<" |x1 - x2| <  ! |f(x1) - f(x2)| < !
>0 >0 x1,x2"R

<" (|x1 - x2| <  ! |f(x1) - f(x2)| < ) !
>0 >0 x1,x2"R

(|x1 - x2| < ) '" (|f(x1) - f(x2)| ).
>0 >0 x1,x2"R
1
x1 = n, x2 = n +  > 0
n
1
n0 n n0 |x1 - x2| = <  |f(x1) -
n
f(x2)| = |n2 - (n + 1)2| = |2n - 1| 1 =
1
c) f(x) = , x " (0, 1] x1 =
x
1 2 1
, x2 = |x1-x2| = <  n |f(x1)-f(x2)| =
n n n
n 1 1
|n - | = n =
2 2 2
f : [a, b] R
[a, b]
f : Ux R
0
f x0
A " R  : U0 R

f(x) - f(x0) = A (x - x0) + (x - x0)


x"Ux0
"x
"f
lim (x - x0) = 0,
xx0
"x = x - x0 "f = f(x) - f(x0)
"x
A f x0
A = f (x0) A"x f x0
A (x - x0) = df(xo, "x)
f(x) - f(x0)
= A + ("x),
"x
f(x) - f(x0)
f (x0) = lim .
"x0 - x0
x
a) f(x) = x2 x0 = 1
f x0 = 1
"x = x - x0 = x - 1
"f "f f(x) - f(1) x2 - 1
(x0) = (1) = =
"x "x x - 1 x - 1
"f "f
lim (x0) = lim (1) =
"x0 x1
"x "x
x2 - 1
lim = lim(x + 1) = 2.
x1 x1
x - 1
f (1) - 2
b) f(x) = x2, x " R
Df = R
(x2) = 2x, x " R.
x0 " R
Df f(x0 + "x) - f(x0)
lim (x0) = lim =
"x0 "x0
"x "x
(x0 + "x)2 - x2 (x0 + "x - x0)(x0 + "x + x0)
0
lim = lim =
"x0 "x0
"x "x
"x(2x0 + "x)
lim = lim (2x0 + "x) = 2x0.
"x0 "x0
"x
x0 f (x) = (x2) = 2x x " R
f, g x0  " R
f
f ą g fg f = 0 x0

g
1) (f ą g) = f ą g
2) (fg) = f g + fg
3) (f) = f
f g-fg
4) (f ) =
g g2
f(x) = signx x2, x " R
ńł
ł -2x jeżeli x < 0
ł
f (0) = 0 jeżeli x = 0
ł
ół
2x jeżeli x > 0
(x) = signx, x " R
 (x) = x2, x " R
f   f(x) = (x) (x), x " R
x " (-", 0) *" (0, +")
f (x) =  (x) (x) + (x)  (x) =

(-1) 2x jeżeli x < 0
1 2x jeżeli x > 0
f x0 = 0
"f sign(0 + "x) (0 + "x)2
lim (0) = lim =
"x0 "x0
"x "x
(sign"x) ("x2)
lim = lim sign"x "x = 0.
"x0 "x0
"x
 
f (0) = 0
f : (a, b) Y
(a, b) Y

f (x) > 0 (" f (x) < 0.
x"(a,b) x"(a,b)
Y y " Y
1
(f-1) (y) = , y = f(x) ! x = f-1(y).
f (x)
1
"
arcsin (x) = , x " (-1, 1).
1 - x2
Ą
f = sin (-Ą , )
2 2
Ą Ą
f (x) = sin (x) = cos x > 0, x " (- , ).
2 2
1 1 1 1
" "
(f-1) (x) = = = = .
cos y cos arcsinx
1 - x2
1 - sin2 arcsinx
f : Ux R g : Uf(x ) R f(Ux ) " Uf(x )
0 0 0 0
f X0 g u0 = f(x0)
g ć% f x0
(g ć% f) (x0) = g (f(x0))f (x0).
f(x) > 0 x " Df
1
(ln f(x)) = f (x).
f(x)

h(x) = (f(x))g(x) '" f(x) > 0.
x"Df
h(x) = eg(x) ln f(x), x " Df

f (x)
h (x) = eg(x) ln f(x) g (x) ln f(x) + g(x) , x " Df.
f(x)
f : Ux R f(1) Ux
0 0
f(1) x0 2
x0 f(2)
n f
f(n) = (f(n-1)) , n " N.
K f
(x0, f(x0))
y - f(x0) = f (x0)(x - x0).
K (x0, f(x0))
K f
(x0, f(x0))
1
y - f(x0) = - (x - x0) f (x0) = 0


f0(x0)
x = x0 f (x0) = 0
f : Df R f K =
{(x, f(x)) : x " Df} K K :

y = f(x)
x " Df
K f P =
(x0, f(x0)
K P f x0
s
= [1, f (x0)]
s
P
K P
f : [a, b] R
[a, b] (a, b) f(a) = f(b)  " (a, b)
f () = 0
(, f())
K = {(x, f(x)) : x " [a, b]}  " (a, b)
Ox
f : [a, b] R
[a, b]  " (a, b)
f(b) - f(a)
= f ().
b - a
f : [a, b] R a, b " R# [a, b]
L 0

|f(x1) - f(x2)| L |x1 - x2|.
x1,x2"[a,b]
f : [a, b] R (a, b) f
L
L = sup{|f (x)| : x " (a, b)}.
x1, x2 " (a, b) x1 < x2 [x1, x2]
 " (x, y)
f(x1) - f(x2)
f () = .
x1 - x2
|f(x1) - f(x2)| |f ()| |x1 - x2| L |x1 - x2|.
a) f(x) = sin x, x " R
|f(x1) - f(x2)| = | sin x1 - sin x2| =
x1 - x2 x1 + x2
|2 sin cos |
2 2
x1 + x2 x1 - x2
2 | cos | | sin |
2 2
|x1 - x2|
2 1 = |x1 - x2|.
2
f (x) = cos x, x " R L = sup{|f (x)| : x " R} = 1
b) f(x) = xą x 0 ą " (0, 1)
[0, ") [0, ")
f : [a, b] R
(a, b) f (x) > 0, x " (a, b) f (x) < 0, x " (a, b)
f (a, b)
f g
x0 " int(Df)
lim f(x) = 0 = lim g(x)
xx+ xx+
0 0
lim f(x) = " = lim g(x),
xx+ xx+
0 0

lim f(x) = 0 = lim g(x)
xx- xx-
0 0

lim f(x) = " = lim g(x)
xx+0-
xx-
0
R#

f (x) f (x)
lim lim ,
g (x)
xx+ xx- g (x)
0 0

f(x) f(x)
lim lim
g(x)
xx+ xx- g(x)
0 0

f(x) f (x) f(x) f (x)
lim = lim lim = lim .
g(x) g (x)
xx- g (x)
xx+ xx+ xx- g(x)
0 0 0 0
1) limx0 arcsinx
sin x
1
"
arcsinx 0
H
1-x2
lim = [ ] = lim = 1.
x0 x0
sin x 0 cos x
2) limx" x1000
ex
x1000 " 1000x999 "
H H
lim = [ = lim = [ ] =
x" x"
ex " ex "
1000! 1000!
. . . = lim = [ ] = 0.
x"
ex "
x2
2
3) limx0 Ą arctgx
2
x
x2
2 2
Ą
lim arctgx = [00] = lim eln( arctgx) =
x0 x0
Ą
2 2
Ą
lim ex ln ( arctgx)
x0

2
ln arctgx
2 "
Ą
lim x2 ln arctgx = [0 "] = lim = [ ] =
1
x0 x0
Ą "
x2
1 2 1

2
Ą 1+x2 1 x x2 1
arctgx
Ą
= lim = - lim = (- ) 1 0 = 0.
2
x0 x0
- 2 arctgx 1 + x2 2
x3
x2
2
limx0 Ą arctgx = e0 = 1.
f : Ux R
0
f
x0 Sx x0
0
ł ł

ł
f(x) < f(x0) f(x) > f(x0)łł .
x"Sx0 x"Sx0
f : Ux R x0
0
f (x0) = 0
f(x) = |x| x " R x0 = 0
f (0)
x0
an + bn = cn n 2 a, b, c " Z
f :

Ux R Sx x0 - f (x) >
0 0 x"Sx0

0 '" + f (x) < 0, f x0
x"Sx0

- f (x) < 0 '" + f (x) > 0, x0
x"Sx0 x"Sx0
f : Ux R
)
Cn(Ux ) n = 2k k " N
0
f (x0) = f (x0) = . . . = f(n-1)(x0) = 0,
f(n)(x0) = 0 f x0

f(n)(x0) < 0 f(n)(x0) > 0
f(x) = |x| x " R x0 = 0

-1 x < 0
f f (x) =
1 x > 0
x0 = 0
f(x) = ex + e-x + 2 cos x
f (x) = ex - e-x - 2 sin x '" f (x) = 0 ! x = 0,
f (x) = ex + e-x - 2 cos x '" f (0) = 0,
f (x) = ex - e-x + 2 sin x '" f (0) = 0,
f(4)(x) = ex + e-x + 2 cos x '" f(4)(0) = 4 > 0.
f x0 = 0
R
A " R
(xn) " A (xn ) A
k
limk" xn = x " A
k
a) [0, 1] R
b) A = [0, 1] \ Q
R
A " R

K0(x, r) " A
x"A
K0(x,r)
A " R R R \ A
A " R R

[ ! x " A].
(xn)"A limn" xn=x
(a, b) R [a, b]
{a}, {b}, . . .
" R
A " R R
R A
f : A R
A R A
 " A
f() = inf{f(x) : x " A}
 " A
f() = sup{f(x) : x " A}.
f : A R f
Int(A) f A
A
f " A f() = 0
f
f
f A

a) f(x) = (1 - x2)(1 + 2x) [-1, 1]
f(-1) = f(1) = 0
f
x(1 - 4x2)

f (x) = .
(1 - x2)(1 + 2x2)
1
0, -1,
2 2
"
1 3 2 1
f(1) = f(-1) = 0, f(0) = 1, f(- ) = = f( ).
2 4 2
f 0
f(-1) = f(1) = 0
"
3 2
2 2 4
" f(-1) = f(1) =
"
b) f(x) = x2 - 3x + 2 + 3x - x2, x " [0, 1] *" [2, 3]
f
"
f(0) = f(1) = f(2) = f(3) = 2.
f
2x - 3 3 - 2x
" "
f (x) = + .
2 x2 - 3x + 2 2 3x - x2
" "
3 3- 5 3+ 5 3
f (x) = 0 ! x = (" x = (" x = " Df
2 2 2 2
" "
3 - 5 3 + 5 3
f( ) = f( ) = .
2 2 2
"
f 1, 2, 3, 4 2
" "
3- 5 3+ 5 3
2 2 2
f : (a, b) R
f (a, b)
(a, b) x0 " (a, b)
Sx x0 (x0, f(x0))
0
f
f (a, b)
f : (a, b) R x0 " (a, b)
x0
x0
f
f(x) = signx x2 x " R

-x2 x 0
f(x) =
x2 x > 0
ńł
ł -2x jeżeli x < 0
ł
f (x) = 0 jeżeli x = 0
ł
ół
2x jeżeli x > 0
ńł
ł -2 jeżeli x < 0
ł
f (x) = jeżeli x = 0
ł
ół
2 jeżeli x > 0
f (-", 0) (0, ") x0 = 0
f
f x0 x = x0
f

lim f(x) " {-", +"} lim f(x) " {-", +"} .
xx- xx+
0 0
x = x0 f
f
x = 0 f(x) = xn x " R

-" jeżeli n = 1, 3, . . .
lim f(x) =
+" jeżeli n = 2, 4, . . .
x0-
lim f(x) = +" n " N.
x0+
f +" -"
f : (-", a) *" (b, ") R
x f(x)

f(x) f(x)
lim = m " R lim = m
x-" x+"
x x

lim (f(x) - mx) = k " R lim (f(x) - mx) = k ,
x-" x+"
y = mx + k f
k " R m = 0
1
Df f(x) = x ln (e + )
x
x " Df f
Df f
1 1
x = 0 '" e + > 0 ! x " (-", - ) *" (0, ")

x e
ex + 1 1 1
x = 0 '" > 0 ! x = 0 '" e(x + )x > 0 ! x " (-", - ) *" (0, ")

x e e
f(x) 1
lim = lim ln (e + ) = 1 = m.
x-" x-"
x x
1 1
lim (f(x) - mx) = lim (x ln (e + ) - x) = lim x(ln (e + ) - 1) = [(-") 0].
x-" x-" x-"
x x
[" 0]
1
ln (e + ) - 1 0
H
x
lim (f(x) - x) = lim = [ ] =
1
x-" x-"
0
x
1 1
(- )
1
x2 1 1
e+
x
lim = lim = = k.
1 1
x-" x-"
- e + e
x2 x
1
y = x + f
e
x = -1
e
1 1
lim x ln (e + ) = [(- ) (-")] = +".
-
1
x e
x-
e
x = -1
e
f
x = 0
f
1
lim f(x) = lim x ln (e + ) = [0 "] =
x)+ x0+ x
1
ln (e + ) "
H
x
lim = [ ] =
x0+ 1 "
x
1 1
(- )
1
x2 1 1
e+
x
lim = lim = [ ] = 0.
x0+ 1 x0+ 1
(- ) e + "
x2 x
x = 0
+"
f(x) 1
lim = lim ln (e + ) = 1 = m
x+" x+"
x x
1
lim (f(x) - mx) = lim x ln (e + ) - x) =
x+" x+"
x
1
lim x[ln (e + ) - 1] = [" 0] =
x+"
x
1
ln (e + ) - 1 0
H
x
lim = [ ] =
1
x+"
0
x
1 1
(- )
1
x2
e+
x
lim =
1
x+"
-
x2
1 1
lim = = k.
1
x+"
e + e
x
1
y = x + f
e
f
f : {1, . . . , n} R
t ft
t t
n
f
t
ft+1 - ft
, t = 1, 2, . . . , n.
ft
f n
t+"t
f (0, ") R
t f(t)
f
f(t + "t) - f(t)
lim
"t0
"t f(t)
f(t + "t) - f(t) f (t)
lim = .
"t0
"t f(t) f(t)
f
x
f : (0, ") (0, ")
x f(x)
(0, ")
x0 "x
"f f(x0 + "x) - f(x0)
df
(x0) =
"x "x
"x x0
"x 0
"f f(x0 + "x) - f(x0)
df
(x0) = = f (x0).
"x "x
x f (x)
"f = f(x0 + "x) - f(x0) H" f (x0)"x.
"x
f (x0) "x
f : (0, ") (0, ")
x f(x)
(0, ") x0 " (0, ") "x > 0
f(x0 + "x) - f(x0) "x
:
f(x0) x0
f [x0, x0 + "x]
E
f(x0 + "x) - f(x0) x0 x0
lim = f (x))
"x0
"x f(x0) f(x0)
f x0 E(x0)
f p% q% q H" pE(x)
f : Ux R Ux x0 " R
0 0
f Cn Ux n " N
0
f n f
Cn(Ux ) f " Cn(Ux ) C0(Ux )
0 0 0
Ux ) C"(Ux ) n
0 0
n " N
Cn(A) A
R C2((0, 1)) (0, 1)
f Cn-1
[a, b] n
 " (a, b)
n-1

f(k)(a)
f(b) - f(a) = (b - a)k +
k!
k=1

n - 1
f(n)()
(b - a)n .
n!

n-1

f(k)(x)
(") g(x) = f(b) - f(x) - (b - x)k - A(b - x)n,
k!
k=1
A g(a) = 0 g(b) = 0
g(a) = 0 g(b) = 0 g [a, b]
(a, b)
n-1

f(k+1)(x)
g (x) = -f (x) - (b - x)k+
k!
k=1
n-1

f(k)(x)
k(b - x)k-1 + An(b - x)n-1 =
k!
k=1
n-2

f(k)(x) f(n)(x)
-f (x) - (b - x)k - (b - x)n-1+
k! (n - 1)!
k=1
n-1

f(k)(x)
f (x) + (b - x)k-1 + An(b - x)n-1 =
(k - 1)!
k=2
n-2

f(k+1)(x) f(n)(x)
- (b - x)k + (b - x)n-1+
k! (n - 1)!
k=1
n-2

f(k+1)(x)
(b - x)k + An(b - x)n-1.
k!
k=1
f(n)(x)
g (x) = - (b - x)n-1 + An(b - x)n-1.
(n - 1)!
f(n)()
 " (a, b) g () = 0 A =
n!
A (")
a) f : Ux R
0
n-1

f(k)(x0)
f(x) = (x - x0)k+
k!
k=0
f(n)()
(x - x0)n ,
n!

x " Ux  = x0 + (x - x0)  " (0, 1)
0
b) x0 = 0
n-1

f(k)(0)
f(x) = xk+
k!
k=0
f(n)(x))
xn ,
n!

x " U0  " (0, )
a) f(x) = sin x, x " R C" R
x0 " R x " Ux n " N
0
n-1 Ą

sin (x0 + k )
2
sin x = (x - x0)k + Rn(x0, x),
k!
k=0
Ą
sin (+n )
2
Rn(x0, x) = (x - x0)n  = x0 + (x - x0)
n!
b) a) x0 = 0 k f(x) = sin x
x0 = 0

0 n = 2k
f(k)(0) =
(-1)k n = 2k + 1, k " N0.
sin x
f(x) = sin x
n-1

(-1)k
sin x = x2k+1+
(2k + 1)!
k=0
sin (x + (2n + 1)Ą )
2
x2n+1 .
(2n + 1)!

2n + 1
R2n 2n
a)
x3
sin x H" x - , x " [- , ].
6
1
= 1 =
10
Ą Ą
sin (x+5 ) | sin (x+5 )|
2 2
R5(0, x) = x5 |R5(0, x)| = |x|5
5! 120
1
= 1 |R5(0, x)|
120
1 1 1 1
= |R5(0, x)| =
10 120 10000 1200000
b) sin 10o
10-6 = 0.000001
Ą
10o
18
Ą
Ą sin ( + (2n + 1)Ą ) Ą
18 2
|R2n+1(0, )| = | ( )2n+1|
18 (2n + 1)! 18
Ą
(18)2n+1 22n+1
< .
(2n + 1)! 92n+1(2n + 1)!
Ą 1
n |R2n+1(0, )| <
18 1000000
23 4
n = 1 ! |R3| < =
936 81
25 25 1 1
n = 2 ! |R5| < = = <
959! 9612345678 97140 1000000
Ą Ą3
sin 10o H" -
18 1836
f(x) = cos x
n-1

(-1)k cos (x + nĄ)
cos x = x2k + x2n
(2k)! (2n)!
k=0

2n
f : (a, b) R
F : (a, b) R f

F (x) = f(x), x " (a, b)
F f : (a, b) R
Ś(x) = F (x) + C
f
Ś f (a, b)
Ś(x) = F (x) + C
!:

(F (x) + C) = F (x) + 0 = f(x), x " (a, b).
!: Ś f
(F - Ś) (x) = 0
F - Ś = const
= 0 I
Ś(x) = F (x) + C x " (a, b)
f

f f(x)dx


f(x)dx = {F : (a, b) R : F (x) = f(x), x " (a, b)}.

f(x)dx = F (x) + C, C " R,
F f

dx
"
= arcsinx + C, x " (-1, 1).
1 - x2
1
"
(arcsinx) = , x " (-1, 1).
1 - x2
1.  " R

f(x)dx =  f(x)dx,
2. f, g : (a, b) R

(f(x) + g(x))dx = f(x)dx + g(x)dx.
g : (a, b) R
(a, b) w : (ą, ) R w((ą, )) " (a, b)
C1 (a, b)

g(w(x))w (x)dx = G(w(x)) + C,
G g

I = [2 cos4 x sin x - 3 cos x sin3 x]dx.

I = 2 cos4 x sin xdx + (-3) sin3 x cos xdx.
I = 2I1 - 3I2,

I1 = cos4 x sin xdx I2 = sin3 x cos xdx.
I1 I2



t5 cos5 x
cos x = t

I1 = = t4(-dt) = - t4 = - + C = - + C.
- sin xdx = dt

5 5



t4 sin4 x
sin x = t

I2 = = t3dt = + C = + C.

cos xdx = dt
4 4

f (x)dx
= ln |f(x)| + C, x " (a, b),
f(x)
f(x) > 0 x " (a, b)


f (x)dx

= 2 f(x) + C, x " (a, b),
f(x)
f(x) > 0 x " (a, b)
F f

1
f(ax + b)dx = F (ax + b) + C.
a
f, g : (a, b) R
C1

(") f(x)g (x)dx = f(x)g(x) - g(x)f (x)dx.
(f(x)g(x)) = f (x)g(x) + f (x)g(x),
f(x)g (x) = (f(x)g(x)) - f (x)g(x)
(")

a) x cos xdx b) ex cos xdx
a)



f(x) = x g (x) = cos x

x cos xdx = =

f (x) = 1 g(x) = sin x

x sin x - sin xdx = x sin x + cos x + C.

b) I2 = ex cos xdx I1 = ex sin xdx I1 I2
I1


f(x) = sin x g (x) = ex

I1 = =

f (x) = cos x g(x) = ex

ex sin x - ex cos xdx = ex sin x - I2.
I2


f(x) = cos x g (x) = ex

I2 = =

f (x) = - sin x g(x) = ex
-ex sin x + I1.
I1 = ex sin x - (ex cos x + I1)

1
I1 = ex cos xdx = ex(sin x - cos x) + C.
2

1 1
I2 = ex sin xdx = ex cos x+I1 = ex cos x+ ex(sin x-cos x)+C = ex(cos x+sin x)+C.
2 2

dx
(1) In(a)(x) = , n " N, a " R,
(x2 + a2)n

(2) In(x) = sinn xdx, n " N0.
In(a)(x)
a = 0
x-(2n-1)
(3) In(0)(x) = - + C, n = 1, 2, . . . .
2n - 1
a = 0 n = 1


dx 1 dx
I1(a)(x) = = =
x2 + a2 a2 (x)2 + 1
a


x
1 adt 1
= t

a
= = arctgt + C.
1

dx = dt
a2 t2 + 1 a
a
1 x
(4) I1(a)(x) = arctg + C.
a a
a = 0 n 2


1 a2dx 1 a2 + x2 - x2
In(a)(x) = = dx =
a2 (x2 + a2)n a2 (x2 + a2)n

1 dx 1 x2dx
- =
a2 (x2 + a2)n-1 a2 (x2 + a2)n
1 1
In-1(a)(x) - Jn(a)(x),
a2 a2
x2dx
Jn(a)(x) = , n " N, a " R.
(x2 + a2)n
Jn(a)(x)

1 2x
Jn(a)(x) = x dx =
2 (x2 + a2)n


1 2x
f(x) = x g (x) =

2 (x2+a2)n

=
(x2+a2)-n+1
1
f (x) = g(x) =
2 -n+1

1 (x2 + a2)-n+1 1 1 dx
x - =
2 (-n + 1) 2 (-n + 1) (x2 + a2)n-1
1 (x2 + a2)-n+1 1 1
x - In-1(a)(x).
2 (-n + 1) 2 (-n + 1)

1 1 1 (x2 + a2)-n+1 1 1
In(a)(x) = In-1(a)(x) - x - In-1(a)(x) =
a2 a2 2 (-n + 1) 2 (-n + 1)
1 x 2n - 3
(5) + In-1(a)(x), n = 2, 3, . . . .
2(n - 1)a2 (x2 + a2)n-1 2(n - 1)a2

dx
(x2+4)2
2 2 - 3 1 x
I2(2)(x) = I1(2) + =
2(2 - 1)22 2 22 (x2 + 4)
1 x 1 1
arctg + + C.
16 2 8 x2 + 4

In(x) = sinn xdx n " N0
n = 0

I0(x) = dx = x + C.
n = 1

I1(x) = sin xdx = - cos x + C.
n > 1

In(x) = sinn xdx = sinn-2 x sin2 xdx = sinn-2 x(1 - cos2 x)dx =

sinn-2 xdx + Jn(x),

Jn(x) = sinn-2 x cos2 xdx = cos x[sinn-2 cos x]dx =


f(x) = cos x g (x) = sinn-2 x cos x

=
sinn-1 x

f (x) = - sin x g(x) =
n-1
1 1
cos x sinn-1 x + In(x).
n - 1 n - 1
n - 1 1 1
In(x) = In-2(x) - ( cos x sinn-1 x + In(x)),
n n - 1 n - 1
n - 1 1
In(x) = In-2(x) - sinn-1 x cos x.
n n

sin4 xdx
3 1
I4(x) = I2(x) - sin3 x cos x.
4 4
1 1 1 1
I2(x) = I0(x) - sin x cos x = x - sin x cos x.
2 2 2 2

3 1 1 1
sin4 xdx = ( x - sin x cos x) - sin3 x cos x.
4 2 2 4
Pn(x)
f(x) = x " Df
Qn(x)
n < m f
A
1. f(x) = a = 0

ax+b
A
2. f(x) = a = 0

ax2+bx+c
Ax+B
3. f(x) = a = 0

ax2+bx+c

Adx dx A
= A = ln |ax + b| + C.
ax + b ax + b a
ą " = b2 - 4ac = 0
ax2 + bx + c = a(x - p)2

dx 1 dx -1
= = + C.
ax2 + bx + c a (x - p)2 a(x - p)
 " < 0
b "
ax2 + bx + c = a(x - p)2 + q, p = - , q = - .
2a 4a
"
ax2 + bx + c = a[(x - p)2 - ].
4a2

dx 1 dx
= =
"
ax2 + bx + c a - p)2 + (- )
(x
4a2


1 dx "
, A = - .
a (x - p)2 + A2 4a2

dx 1 1 x - p
= arctg( ) + C =
ax2 + bx + c a A A
1 1 x - p

arctg( + C.
" "
a
- -
4a2 4a2

dx
x2+x+1
" = 1 - 4 = -3 < 0
"
1 1 3 1 3
x2 + x + 1 = (x2 + 2 x + ) + = (x + )2 + ( )2.
2 4 4 2 2

dx dx
"
= =
1 3
x2 + x + 1
(x + )2 + ( )2
2 2
1 1 1
" "
arctg( (x + )) + C =
3 3
2
2 2
" "
2 3 2 3 1
arctg( (x + )) + C.
3 3 2
ł " > 0
ax2 + bx + c = a(x - x1)(x - x2)

dx 1 dx
=
ax2 + bx + c a (x - x1)(x - x2)
1 1 1 1 1
= + .
(x - x1)(x - x2) x1 - x2 x - x1 x2 - x1 x - x2

dx 1 1 1 1
= ln |x - x| + ln |x - x2| + C.
ax2 + bx + c a x1 - x2 a x2 - x1
dx
3x2-9x+6
3x2 - 9x + 6 = 3(x2 - 3x + 2) = 3(x - 1)(x - 2).

dx 1 dx
= .
3x2 - 9x + 6 3 (x - 1)(x - 2)
1 A B
= + .
(x - 1)(x - 2) x - 1 x - 2
1 = A(x - 2) + B(x - 1).
x = 2 ! B = 1 x = 1 ! A = -1

1 -1 1 1 x - 1
I = [ + ]dx = ln | | + C.
3 x - 2 x - 1 3 x - 2
mx+k
3. f(x) =
ax2+bx+c
f

f (x)
dx
f(x) ax2+bx+c

k
x +
m
I = m dx =
ax2 + bx + c

2ak
m 2ax +
m
dx =
2a ax2 + bx + c

m (2ax + b) + (2ak - b)
m
dx =
2a ax2 + bx + c

m 2ax + b m 2ak dx
dx + ( - b) =
2a ax2 + bx + c 2a m ax2 + bx + c

m 2ak - bm dx
ln |ax2 + bx + c| + .
2a 2 ax2 + bx + c

xdx
x2+x+1

1 2xdx 1 2x + 1 - 1
I = = dx =
2 x2 + x + 1 2 x2 + x + 1

1 2x + 1 1 dx
dx - =
2 x2 + x + 1 2 x2 + x + 1
" "
1 1 2 3 2 3 1
ln(x2 + x + 1) - arctg( (x + )) + C.
2 2 3 3 2
f : I R I = [a, b]
n I
[x0, x1], [x1, x2], . . . , [xn-1, xn],
a = x0 < x1 < . . . < xn = b, n " N
i i = xi - xi-1 i [xi-1, xi] i =
1, . . . , n
n
"n = max{i : 1 i n}.
[xi-1, xi] i
xi-1 i xi i " {1, . . . , n}
n

n = f(i)i.
i=1
( n)n"N I
( n)n"N
I
lim "n = 0.
n"
( n) I
i i " {1, . . . , n} n " N
(n) Ł
n

Ł = lim f()i,
n"
i=1
f R I Ł
f [a, b]

b
Ł = f(x)dx.
a
mi = inf{f(x) : x " [xi-1, xi]}, Mi = sup{f(x) : x " [xi-1, xi]},
n

sn = mii
i=1
n

Sn = Mii.
i=1
sn Rn Sn, n " N,
n [a, b]

b
f(x)dx
a
lim (Sn - sn) = 0
n"
( n)
R
R
f [a, b]
( n) [a, b] (sn) (Sn)
[xi-1, xi] f [xi-1, xi]
i " [xi-1, xi] f(i) " [mi, Mi]
n n n

sn = mii f(i)i Mii = Sn
i=1 i=1 i=1
mi Mi xi-1, xi]
f [a, b] > 0
 > 0 |x - x | <  |f(x ) - f(x )| <
> 0  > 0 i < 
n

i = 1, . . . , n |Mi - mi| < |Mi - mi|i < Sn - sn <
i=1
b-a
limn"(Sn - sn) = 0

1 x " Q
f(x) =
0 x " R \ Q
R
S = b - a s = 0
A B
A B f : A B
A A
B " A B = A f : A B

card(") = 0.
card({1}) = card({a}) = 1, . . .
card({1, 2, . . . , n}) = n, . . . .
5!0
card(N) = 5!0.
5!0
card(Z) = card(Q) = 5!0.
A A
(an)n"N
A = {a1, a2, . . .}.
card(R) = c.
a b
A a B b C C " B
card(A) = card(C) a b card(A) = card(B)

A B a < b
5!0 < c
A
card(A) < card(P(A)).
P(A) A
A
card(N) = 5!0 card(P)(N) = c
A " R > 0
A (ai, bi) i " N
"

(ai, bi) " A
i=1
"

|bi - ai| < .
i=1
R
f : I R R I = [a, b] f
f [a, b] [a, b]
R
[a, b] R
[a, b]
f f
f R [a, b] |f| R
f R f R
[a, b]  " R

b b
f(x)dx =  f(x)dx.
a a
f g R [a, b]
R

b b b
(f(x) + g(x))dx = f(x)dx + g(x)dx.
a a a
f R [a, b]
c " (a, b)

c b
f(x)dx = f(x)dx + f(x)dx.
a c
f R [a, b] f(x) 0 x " [a, b]

b
f(x)dx 0.
a
f g R [a, b] f(x) g(x) x " [a, b]

b b
f(x)dx g(x)dx.
a a

b b a
f(x)dx f(x)dx = - f(x)dx
a a b
R [a, b]

b
1
m f(x)dx M.
b - a a
"

3
I = 3 + x3dx
1
"
m = 2, M = 30, b - a = 2.
"
2 2 I 30 2.
"
I " [4, 2 30]
f [a, b]  " [a, b]

b
f(x)dx = (b - a) f().
a
f R [a, b]

x
Ś(x) = f(t)dt, x " [a, b].
a
f R [a, b]
a) Ś [a, b]
b) f x = t Ś
f(x) Ś (x) = f(x)

x3
Ś(x) = cos t2dt.
1
x
1
x3
x
Ś(x) = - cos t2dt + cos t2dt.
1 1
Ś
1 1
Ś (x) = - cos x2(- ) + cos x6(3x2) = cos x2 + 3x2 cos x6.
x2 x2
1. f : [a, b] R [a, b]
2.  : [ą, ] [a, b]
a) (ą) = a () = b
b)  C1 [ą, ]

b 
f(x)dx = f((t)) (t)dt.
a ą
2
1

sin dx
Ą x
I =
1
x2
Ą
ńł ł

ł x t ł
ł 1 żł
= t

1
x
I = Ą =
1
Ą
ł - dx = dt
ł
ół ł
2 Ą
x2

Ą 2
Ą
Ą
2
- sin tdt = sin tdt =
Ą
Ą
2
Ą
Ą
- cos t|Ą = - cos Ą + cos = -(-1) + 0 = 1.
2
2
f g C1 [a, b]

b b
f(x)g (x)dx = [f(x) g(x)]|x=b - f (x)g(x0dx.
x=a
a a

1
I = x arctgxdx
0

f(x) = arctgx g (x) = x
I = =
1 x2
f (x) = g(x) =
1+x2 2

1
x2 1 x2dx
arctgx|1 - =
0
2 2 1 + x2
0

1
1 1 (1 + x2) - 1
arctg1 - dx =
2 2 1 + x2
0
Ą 1 1 Ą 1 Ą Ą 1
- + arctgx|1 = - + = - .
0
8 2 2 8 2 8 4 2
f, g : [a, b] R
f(x) g(x), x " [a, b].
Dx Ox

a x b
Dx :
f(x) y g(x)
Dy Oy
 : [c, d] R  : [c, d] R
y (y) y (y)
(y) (y), y " [c, d].
Dy

c y d
Dy :
(y) x (y)
Dx Dy


b d
|Dx| = [g(x) - f(x)]dx |Dy| = [(x) - (x)]dy .
a c
D
D = D1 *" D2 *" . . . *" Dn,
n

|D| = |Dk| = |D1| + . . . + |Dn|.
k=1
a) D f
g f(x) = x2 x " R g(x) = x5 x " R |D| D
a) D Ox

0 x 1
D :
x5 y x2

1
x3 x6 1 1 1
|D| = |Dx| = [x2 - x5]dx = [ - ]|1 = - = .
0
0 3 6 3 6 6
1
b) D y = 2x - x2 x -
4
4y + 6 = 0
1 x+6
D y = 2x - x2 y =
4 4
1 x + 6
2x - x2 = ! x = -1 (" x = 6.
4 4

-1 x 6
D = Dx =
1 x+6
2x - x2 y
4 4

6
1 3 1
|D| = |Dx| = [( x + ) - (2x - x2)]dx =
-1 4 2 4
1 3 1
[ x2 + x - x2 + x3]|6 =
-1
8 2 12
62 3 6 1 1 -3 1 125
[ + - 62 + 63] - [ + + (-1)3] = . . . = .
8 2 12 8 2 12 24
c) y = ln x y = x - 1 y = -1

1 1
0 x x 1
e e
(Dx)1 : (Dx)2 :
-1 y x - 1 ln x y x - 1.
D (Dx)1 (Dx)2 Ox
1
1
e
|D| = |(Dx)1 + |(Dx)2| = [(x - 1) - (-1)]dx + [(x - 1) - ln x]dx.
1
0
e
D Oy

-1 x 0
Dy :
y + 1 x ey

0
y2 e - 2
|D| = |Dy| = [ey - y - 1]dy = [ey - - y]|0 = . . . = .
-1
-1 2 2e
R
f : D R D
(-", a] -" [a, +") +"
D = (-", +")
D = (-", a] a " R f R
Dą = [ą, a] " (-", a]

a
f(x)dx
-"

a
f(x)dx
-"

a
limą-" ą f(x)dx " R

0 0
2xdx dx
dx = lim =
A-"
-" x2 + 4 A x2 + 4


x t

t = x2

A A2 =


dt = 2xdx

0 0

0
dt
lim = lim ln |t + 4||0 = lim [ln 4 - ln (A2 + 4)] = -".
A2
A-" A-" A-"
A2 t + 4

"
f(x)dx
-"

a "
f(x)dx f(x)dx
-" a

" +" a +"
f(x)dx f(x)dx = f(x)dx + f(x)dx
-" -" -" a

a +"
f(x)dx f(x)dx
-" a

+"
f(x)dx
-"

+"
2xdx
.
-" x2 + 4

0
f(x)dx
-"
f, g : [a, ") R R [a, b] " [, ")
0 f(x) g(x), x " [a, ").

" "
g(x)dx f(x)dx
a a

" "
f(x)dx g(x)dx
a a

"
x5dx
I1 =
1 (xĄ + 1)(x5 + 1)
x5 (x5 + 1) 1
= , x 1.
(xĄ + 1)(x5 + 1) (x2 + 1)(x5 + 1) x2 + 1

"
dx
I2 =
1
x2+1

" A
dx dx
I2 = = lim = lim arctgx|A =
1
A" A"
1 x2 + 1 1 x2 + 1
Ą Ą Ą
lim [arctgA - arctg1] = - = .
A"
2 4 4
I1
f : (a, b] R R [ą, b] " (a, b]
+
limxa f(x) " {-", +"}

b
I = f(x)dx
a

b
+
limąa ą f(x)dx

1 1
dx dx
" "
I = = lim =
3 3
0
x2 ą0+ ą x2
"
3
lim 3 x|1 = 3.
ą
ą0+
I
R
R
m

I = Ii.
i=1
Ii, i = 1, . . . , m
I I

+"
dx
I = .
-" x2 + 4x + 4

+" -3 -2 1 +"
dx dx dx dx dx
I = = + + + .
-" (x + 2)2 -" (x + 2)2 -3 (x + 2)2 -2 (x + 2)2 1 (x + 2)2

1
dx
I1 =
-2
(x+2)2

1
dx 1
I1 = lim = lim [- ]|1 =
ą
ą-2+ ą (x + 2)2 ą-2+ x + 2
1 1
lim [- + ] = +".
ą-2+ 3 ą + 2

+"
dx
I =
-"
x2+2x+2

+" +"
dx dx
I = = =
-" x2 + 2x + 2 -" (x + 1)2 + 1

+" +"
dt dt Ą
= 2 = 2 lim [arctgA - arctg0] = 2 = Ą.
A"
-" t2 + 1 0 t2 + 1 2
D

"1
x " (0, 1]
3
x2
f(x) =
e1-x x 1
x = 0 y = 0

1 "
dx
"
|D| = + e1-xdx =
3
0 1
x2

1 A
dx
"
lim + lim e1-xdx =
0+ 3
1
x2 A"

A
"
3
lim 3 x|1 + lim e1-xdx =

A"
0+
1
"
"
3
3
lim [3 1 - 3 ] + lim [-e1-A + 1] = 3 + 1 = 4.
A"
0+
X
+ : X X X
(x, y) x + y
R X X
(, x)  x.
X
1) x + y = y + x x, y " X
2) x + (y + z) = (x + y) + z x, y, z " X
3 Ś " X

x + Ś = Ś = x = x.
x"X
4) x " X -x
(-x) + x = x + (-x) = Ś.
5)  (x + y) =  x +  y  " R, x " X
6) ( + ) x = x +  y ,  " R x " X
7) ( x) = () x ,  " R, x " X
8) 1 x = x x " X
< X, +, , R >
< X, +, , R >
(-x)
x " X x " X
-(-x) = x, 0 x = Ś, -x = (-1) x, x + . . . = x = n x, n " N.

n
a) R =< R, +, , R >
b) X = R2 =< R R, +, , R >
x = (x1, x2) y = (y1, y2)
x + y = (x1 + y1, x2 + y2)
 " R
 x = (x1, x2).
c) X = R3 x = (x1, x2, x3)
y = (y1, y2, y3)
x + y = (x1 + y1, x2 + y2, x3 + y3)
 x =  (x1, x2, x3) = (x1, x2, x3).
c) Rn x = (x1, . . . , xn) y = (y1, y2, . . . , yn)
x + y = (x1 + y + 1, x2 + y2, . . . , xn + yn),
x = (x1, x2, . . . , xn),  " R.
Rn
x1, x2, . . . , xm " X
< X, +, , R > 1, 2, . . . , m
2 + 2 + . . . + 2 > 0
1 2 m
m

lxl = 1 x1 + 2 x2 + . . . + m xm = Ś.
l=0
x1, . . . , xm " X <
X, +, , R >
R2 a = (1, 1) b = (-3, -3)
1 = 3, 2 = 1 1a+2b = 3(1, 1)+1(-3, -3) = (0, 0)
a = (1, 1) 1, 2)
,  " R 2 + 2 > 0 (1, 1) +  (1, 2) = (0, 0)
( + , + 2) = (0, 0)

+  = 0
+ 2 = 0
=  = 0
2 + 2 > 0
x x1, . . . , xm
1, . . . , m
m

x = lxl = 1 x1 + . . . + m xm.
l=1
a) x = (1, 1), y = (3, 3) R2 y = 3 x
b) R3 a = (1, 0, 1), b = (0, 1, 0), c = (1, 1, 1)
c = a + b
< X, +, , R > W " X W
X + W
W

x + y " W,  x " W.
x,y"W "R x"W
W = { (1, 1) :  " R} " R2
R2
x1, . . . , xm " X Lin(x1, . . . , xm)
x1, . . . , xm
B = {x1, . . . , xm}
< X, +, , R > X Lin(x1, . . . , xm) = X. m
m = dimX
Rn n
ńł
ł e1 = (1, 0, . . . , 0, 0)
ł
ł
ł
ł
e2 = (0, 1, . . . , 0, 0)
(E)
ł
ł
ł
ł
ół
en = (0, 0, . . . , 0, 1)
{Ś}
Rn
R2
Lin(a), a " R2 \ {(0, 0)}.
m, n " N m n
A : {1, . . . , m} {1, . . . , n} R
(i, j) A(i, j) = aij.
A(ij) = aij A
Matmn
m n
ł łł
a11 a12 . . . a1n-1 a1n
ł
a21 a22 . . . a2n-1 a2n śł
ł śł
ł śł
A =
ł śł
ł ł
am1 am2 . . . amn-1 amn
ai1, ai2, . . . ain-1, ain i A
a1j, a2j, . . . , amj j A
+ : Matmn Matmn Matmn
(A, B) C
ł łł ł łł
a11 a12 . . . a1 n-1 a1n b11 b12 . . . b1 n-1 b1n
ł
a21 a22 . . . a2 n-1 a2n śł ł b21 b22 . . . b2 n-1 b2n śł
ł śł ł śł
ł śł ł śł
A = , B = ,
ł śł ł śł
ł ł ł . . . ł
am1 am2 . . . am n-1 amn bm1 bm2 . . . bm n-1 bmn
ł łł
a11 + b11 a12 + b12 . . . a1 n-1 + b1 n-1 a1n + b1n
ł
a21 + b21 a22 + b22 . . . a2 n-1 + b2 n-1 a2n + b2n śł
ł śł
df
ł śł
C = A + B =
ł śł
ł ł
am1 + bm1 am2 + bm2 . . . am n-1 + bm n-1 amn + bmn
: R Matmn Matmn
(, A)  A
ł łł ł łł
a11 a12 . . . a1 n-1 a1n a11 a12 . . . a1 n-1 a1n
ł
a21 a22 . . . a2 n-1 a2n śł df ł a21 a22 . . . a2 n-1 a2n śł
ł śł ł śł
ł śł
A = ł śł = .
ł śł ł śł
ł ł ł ł
am1 am2 . . . am n-1 amn am1 am2 . . . am n-1 amn
m = n
ł łł
a11 a12 . . . a1n-1 a1n
ł
ł śł
0 a22 . . . a2n-1 a2n śł
ł śł
ł śł
ł śł ,
ł śł
ł
0 0 . . . an-1n-1 an-1n śł
ł ł
0 0 . . . 0 ann
aij = 0 i j i, j " {1, . . . , n}
ł łł
a11 a12 . . . a1n-1 a1n
ł śł
ł śł
a21 a22 . . . a2n-1 0
ł śł
ł śł
ł śł ,
ł śł
ł śł
an-11 an-12 . . . 0 0
ł ł
an1 0 . . . 0 0
aij = 0 i j i, j " {1, . . . , n}
aij = 0 i = j i, j " {1, . . . , n}

aii = 1 aij = 0 i = j i, j " {1, . . . , n}

" : Matmp Matpn Matmn
(A, B) A " B = C
p

cij = ail alj, 1 i p, 1 j n.
s=1
A " (B " C) = (A " B) " C.
A " (B + C) = A " B + A " C
(A + B) " C = A " C + B " C.

1 -1 1 0
A = B =
2 1 1 2

0 -2 1 -1
A " B = , B " A = .
3 2 5 1
A " B = B " A

Matm = Matmm
det : Matm R
not
A det(A) = |A|
1) m = 1
df
det(A) = det([a11]) = a11.
2) m
A " Matm+1
ł łł
a11 a12 . . . a1m a1m+1
ł
a21 a22 . . . a2m a2m+1 śł
ł śł
śł
det(A) = det(ł ) =
ł śł
ł ł
a1m+1 a2m+1 . . . amm+1 am+1m+1
m+1

( ) (-1)i+jaijMij =
j=1
m+1

( ) (-1)i+jaijMij,
i=1
Mij Bij " Matm A
i j i, j " {1, . . . , m + 1}

a11 a12
A =
a21 a22
det(A) = a11a22 - a12a21


a11 a12





a21 a22 = a11a22 - a12a21.

- +


a11 a12 a13


a21 a22 a23



a31 a32 a33 =
a11 a12 a13
a21 a22 a23
[a11a22a33 + a21a32a13 + a31a12a23] - [a31a22a13 + a11a32a23 + a21a12a33].
1)
det(A) = det(AT ),
ł łł
a11 a12 . . . a1j . . . a1m-1 a1m
ł
ł a21 a22 . . . a2j . . . a2m-1 a2m śł
śł
ł śł
ł śł
ł śł
śł
det(ł ) =
ł
ai1 ai2 . . . a1j . . . aim-1 aim śł
ł śł
ł śł
ł śł
ł ł
am1 am2 . . . amj . . . amm-1 amm
ł łł
a11 a21 . . . ai1 . . . am-11 am1
ł
ł a12 a22 . . . ai2 . . . am-12 am2 śł
śł
ł śł
ł śł
ł śł
śł
det(ł )
ł
a1j a2j . . . aij . . . am-1j amj śł
ł śł
ł śł
ł śł
ł ł
a1m a2m . . . aim . . . am-1m amm
2)
3)
4)
5)
6)


a11 a12 . . . a1j + b1j . . . a1m


a21 a22 . . . a2j + b2j . . . a2m


=




am1 am2 . . . amj + bmj . . . amm


a11 a12 . . . a1j . . . a1m a11 a12 . . . b1j . . . a1m


a21 a22 . . . a2j . . . a2m a21 a22 . . . b2j . . . a2m


+ .




am1 am2 . . . amj . . . amm am1 am2 . . . bmj . . . amm
A " Matm Matm
A-1 " Matm
A " A-1 = A-1 " A = I,
I m
ł łł
1 0 . . . 0 . . . 0 0
ł śł
ł 0 1 . . . 0 0 0 śł
ł śł
ł śł
ł śł
ł śł
I =
ł śł
0 0 . . . 1 . . . 0 0
ł śł
ł śł
ł śł
ł ł
0 0 . . . 0 . . . 0 1
A
A-1
A " Matm det(A) = 0

A " Matm
A " Matm
a) (A-1)-1 = A
b) det(A-1) = (det(A))-1
A, B " Matm
(A " B)-1 = B-1 " A-1.
A " Matm
ł łł
a11 a12 . . . a1j . . . a1m-1 a1m
ł
ł a21 a22 . . . a2j . . . a2m-1 a2m śł
śł
ł śł
ł śł
ł śł
ł śł
A =
ł
ai1 ai2 . . . aij . . . aim-1 aim śł
ł śł
ł śł
ł śł
. . .
ł ł
am1 am2 . . . amj . . . amm-1 amm
Dij aij A
Dij = (-1)i+jdetBij
Bij " Matm-1 A
i j
ł łł
D11 D12 . . . D1j . . . D1m-1 D1m
ł
ł D21 D22 . . . D2j . . . D2m-1 D2m śł
śł
ł śł
ł śł
ł śł
ł śł
D =
ł
Di1 Di2 . . . Dij . . . Dim-1 Dim śł
ł śł
ł śł
ł śł
. . .
ł ł
Dm1 Dm2 . . . Dmj . . . Dmm-1 Dmm
A
A " Matm
1
A-1 = DT ,
det(A)
ł łł
D11 D21 . . . Di1 . . . Dm-11 Dm1
ł
ł D12 D22 . . . Di2 . . . Dm-12 Dm2 śł
śł
ł śł
ł śł
ł śł
ł śł
DT =
ł
D1j D2j . . . Dij . . . Dm-1j Dmj śł
ł śł
ł śł
ł śł
. . .
ł ł
D1m D2m . . . Djm . . . Dm-1m Dmm


2 3 2 3

A = " Mat2 det(A) = =
-2 5

-2 5
2 5 - (-2) 3 = 10 + 6 = 16 = 0

A

(-1)1+1det(B11) (-1)1+2det(B12 5 2
D = = .
(-1)2+1det(B21) (-1)2+2det(B22) -3 2
D

5 -3
DT =
2 2
A-1

5 -3
1 -3
5
16 16
A-1 = = .
1 1
2 2
16
8 8

5 -3
2 3 1 0
16 16
A " A-1 = " = .
1 1
-2 5 0 1
8 8

5 -3
2 3 1 0
16 16
A-1 " A = " =
1 1
-2 5 0 1
8 8
ł łł
2 1 0
ł śł
A = 0 1 3 " Mat3
ł ł
1 0 -1


2 1 0


det(A) = 0 1 3 = 1 = 0.



1 0 -1
A A-1
ł łł

1 3 0 3 0 1

ł + - + śł
ł -1 1 1 0
-1
śł
0
ł śł
ł śł
1 0 2 0 2 1
ł śł
D = ł - + - śł =
ł -1 1 0 1 0
śł
0
ł śł
ł śł
1 0 2 0 2 1
ł ł
+ - +

1 3 0 3 0 1
ł łł
-1 3 -1
ł śł
1 ł
ł -2 1 .
3 -6 2
ł łł
-1 1 3
1
ł śł
A-1 = DT = 3 -2 -6 .
ł ł
det(A)
-1 1 2
ł łł ł łł ł łł
2 1 0 -1 1 3 1 0 0
ł śł ł śł ł śł
A " A-1 = 0 1 3 " ł -2 -6 = 0 1 0 .
ł ł 3 ł ł ł
1 0 -1 -1 1 2 0 0 1
A-1 " A = I.
A " Matmn
A
A R(A)
0 R(A) min{m, n}.

1 2 3
A = " Mat23
-2 -4 -6
1 R(A) 2 = min{2, 3}.
A

1 2 3
,
0 0 0
1 R(A) = 1
A " Matmn
Mr r r min{m, n}
Br " Matrr A
A r
r A r

3 1 2 1
A =
6 2 4 2
1 R(A) 2


3 1 3 2 3 1 1 2 1 2 2 1

, , , , , .

6 2 6 4 6 2 2 4 1 2 4 2
R(A) = 1
A-1
A " Matm

A I
A
A-1
A I
A1 I1
An-1 In-1
I A-1

2 3
A =
-2 5
2 3 1 0
1w + 2w
-2 5 0 1
2 3 1 0
1
1w
2
0 8 1 1
3 1
1 0
2 2
2w (-3) + 1w
1 1
2
0 1
8 8
5 -3
1 0
16 16
! A-1
1 1
0 1
8 8
A-1
ł łł
2 1 0
ł śł
A = 0 1 3 .
ł ł
1 0 -1
A-1
2 1 0 1 0 0
0 1 3 0 1 0 1w "! 3w
1 0 -1 0 0 1
1 0 -1 0 0 1
0 1 3 0 1 0 1w (-2) + 3w
2 1 0 1 0 0
1 0 -1 0 0 1
0 1 3 0 1 0 2w (-1) + 3w
0 1 2 1 0 -2
1 0 -1 0 0 1
0 1 3 0 1 0 3w (-1)
0 0 -1 1 -1 -2
1 0 -1 0 0 1
0 1 3 0 1 0 3w + 1w; 3w (-3) + 2w
0 0 1 -1 1 2
1 0 0 -1 1 3
0 1 0 3 -2 -6 ! A-1
0 0 1 -1 1 2
A " Matn = Matnn
 " R A " Matn
ł łł
a11 -  a12 . . . a1 n-1 a1 n
ł
ł śł
a21 a22 -  . . . a2 n-1 a2 n śł
ł śł
df
ł śł
A = A -  I = ł śł
ł śł
ł
an-1 1 an-1 2 . . . an-1 n-1 -  an-1 n śł
ł ł
an 1 an 2 . . . an n-1 an n - 
A " Matn
df
wA() = det(A),  " R.
wA() = 0
A
A
A

2 3
a) A = A
-2 5

2 3 1 0 2 -  3
A = A -  I = -  = .
-2 5 0 1 -2 5 - 
A


2 -  3

wA() = = 2 - 7 + 16.
-2 5 - 

b)
ł łł
2 1 0
ł śł
A = 0 1 3 " Mat3.
ł ł
1 0 -1
ł łł ł łł ł łł
2 1 0 1 0 0 2 -  1 0
ł śł ł śł ł śł
A = A -  I = 0 1 3 -  0 1 0 = 0 1 -  3 ł
ł ł ł ł ł
1 0 -1 0 0 1 1 0 -1 - 


2 -  1 0


wA() = 0 1 -  3 = -3 + 22 +  + 1.


1 0 -1 - 
A
w : R R
 wA()
w(t) = a0tn + a1tn-1 + . . . + = an, t " R
w(A) = a0 An + a1 An-1 + . . . + an I, t " R,
A, I " Matn
nn
A " Matn
wA() = 0, wA(A) = Ś
Ś n n
a0 An + a1 An-1 + . . . + an-1 A + an I = Ś.
(") an I = -a0 An - a1 An-1 - . . . - an-1 A.
A A-1
(") A-1
an A-1 " I = -a0 A-1 " An + . . . - an-1 A-1 " A
-a0 -an-1
A-1 = An-1 + . . . I.
an an

2 3
A =
-2 5
2 - 7 + 16 = 0.
A2 - 7 A + 16 I = Ś.
7 1
16 I = -A2 + 7 A ! A-1 = I - A.
16 16

7 2 3 5 3
0 -
16 16 16 16 16
A-1 = - = .
7 2 5 1 1
0 -
16 16 16 8 8
ł łł
2 1 0
ł śł
A = 0 1 3
ł ł
1 0 -1
ł łł ł łł ł łł
2 1 0 1 0 0 2 -  1 0
ł śł ł śł ł śł
A = A -  I = 0 1 3 -  0 1 0 = 0 1 -  3 .
ł ł ł ł ł ł
1 0 -1 0 0 1 1 0 -1 - 
-3 + 22 +  + 1 = 0.
-A3 + 2 A2 + A + I = Ś.
A-1 = A2 - 2 A - I.
ł łł ł łł ł łł
2 1 0 2 1 0 4 3 3
ł śł ł śł ł śł
A2 = 0 1 3 " ł 0 1 3 = 3 1 0 ł
ł ł ł ł
1 0 -1 1 0 -1 1 1 1
ł łł ł łł ł łł
4 3 3 4 2 0 1 0 0
ł śł ł śł ł śł
A-1 = 3 1 0 - ł 0 2 6 - ł 0 1 0 =
ł ł ł ł
1 1 1 2 0 -2 0 0 1
ł łł
-1 1 3
ł śł
3 ł
ł -2 -6 .
-1 1 2
m n
ńł
ł
a11x1 + a12x2 + . . . + a1nxn = b1
ł
ł
(1)
ł
ł
ół
am1x1 + am2x2 + . . . + amnxn = bn
(1)
aij (i, j) " {1, . . . , m} {1, . . . , n}
x1, . . . , xn
b1, . . . , bm
ł łł
a11 a12 . . . a1n
ł
a21 a22 . . . a2n śł
ł śł
ł śł
A = " Matmn.
ł śł
ł ł
am1 am2 . . . amn
ł łł
x1
ł śł
ł śł
X = " Matn1.
ł ł
xn
ł łł
b1
ł śł
ł śł
B = " Matm1.
ł ł
bm
(1)
(2) A " X = B.
(1) x1, . . . , xn
m
(1) x2 + x2 + . . . + x2 > 0
1 2 n

xi 0.
i"{1,...,n}
B
(1)
(1 ) A " X = Ś
(3) A " X = B,
A " Matn = Matn n X, B " Matn1
(3) (3)
A " X = B ! A-1 " (A " X) = A-1 " B !
(4) X = A-1 " B.
(4)
Wj
xj = , i = 1, . . . , n,
W


a11 a12 . . . a1j . . . a1m


a21 a22 . . . a2j . . . a2m


W = det(A) =




an1 an2 . . . anj . . . ann


a11 a12 . . . b1 . . . a1n-1 a1n


a21 a22 . . . b2 . . . a2n-1 a2n


Wj =




an1 an2 . . . bn . . . ann-1 ann
Wj j
W j = 1, . . . , n
ńł
ł 2x1 + x2 = 1
ł
x2 + 3x3 = 2
ł
ół
x1 - x3 = 3


2 1 0


W = 0 1 3 = 1.


1 0 -1


1 1 0


W1 = 2 1 3 = 10.


3 0 -1


2 1 0


W2 = 0 2 3 = -19.


1 3 -1


2 1 1


W3 = 0 1 2 = 7.


1 0 3
x1 = 10, x2 = -19, x3 = 7
ł łł
-1 1 3
ł śł
A-1 = 3 -2 -6 ,
ł ł
-1 1 2
ł łł ł łł ł łł ł łł
x1 -1 1 3 1 10
ł ł śł ł śł ł śł
X = x2 śł = 3 -2 -6 " ł ł ł -19 .
ł ł ł ł 2 = ł
x3 -1 1 2 3 7
A " Matmn B " Matm1 (1)
X " Matn1
(1) U " Matm(n+1)
ł łł
a11 a12 . . . a1n b1
ł

a21 a22 . . . a2n b2 śł
ł śł
ł śł
U = A B = .
ł śł
ł ł
am1 am2 . . . amn bm
(1)
R(A) = R(U) (R(A) = R(U)).

R(A) = R(U) = n
R(A) = R(U) = r < n
p = n - r
R(A) = R(U) = n
(1) m n
m = n (1)
U

U a" A B ,
A
ńł
ł a x1 + a x2 + . . . + a xn = b
ł 11 12 1 n 1
ł
ł
ł
a x2 + . . . + a xn = b
22 2 n 2
ł
ł
ł
ł
ół
a xn = b
n n n
b
n
xn =
a
n n
xn-1
n x1

x1 + 2x2 = 1
x1 - x2 = 2
U

1 2 1
U =
1 -1 2
a11 = 1 = 0 U

U U1

1 2 1
U1 =
0 -3 1

x1 + 2x2 = 1
-3x2 = 1
-1
x2 =
3
x2
(-1)
x1 + 2 = 1
3
5
x1 =
3
R(A) = R(U) = r < n M " Matrr
ł łł
a11 a12 . . . a1 r-1 a1 r
ł
a21 a22 . . . a2 r-1 a2 r śł
ł śł
ł śł
M = .
ł śł
ł ł
ar1 ar2 . . . ar r-1 ar r
(1) (1r)
ńł
n
ł
a11x1 + a12x2 + . . . + a1 rxr = b1 - a1 kxk
ł
k=r+1
ł
(1r) .
ł
ł n
ół
ar1x1 + ar2x2 + . . . + ar rxr = br - ar kxk
k=r+1
xr+1, . . . , xn
xr+1 = tr+1, . . . , xn = tn.
ńł
ł x1 + 2x2 + x3 = 1
ł
-x1 + x2 + 2x3 = 2
ł
ół
x2 + x3 = 1
ł łł ł łł
1 2 1 1 2 1 1
ł śł ł śł
A = -1 1 2 , U = -1 1 2 2 ,
ł ł ł ł
0 1 1 0 1 1 1
ł łł ł łł ł łł ł łł
1 2 1 1 1 2 1 1 1 2 1 1 1 2 1 1
ł śł ł śł ł śł ł śł
U = -1 1 2 2 a" 0 3 3 3 a" 0 3 3 3 a" 0 1 1 1 .
ł ł ł ł ł ł ł ł
0 1 1 1 0 3 3 3 0 0 0 0 0 0 0 0
R(A) = R(U) = 2

x1 + x2 + x3 = 1 x1 + x2 = 1 - x3
!
x2 + x3 = 1 x2 = 1 - x3
x3 x3 = t
x1 = 0, x2 = 1 - t, x3 = t, t " R
(1) R(A) = R(U) = r < n
M r

n
r
(1)
(1r)
(1 )
r

x1 + x3 = 1 - x2
(1 ) ,
r
x3 = 1 - x2
x1 = 0, x2 = , x3 = 1 - ,  " R
t = 0 (1r)
x1 = 0, x2 = 1 - t, x3 = t, t " R.
t = 0
x1 = 0, x2 = 1, x3 = 0.
(1 )  = 0
r
x1 = 0, x2 = 0, x3 = 1.
(1)
A < X, +, , R > Rn

1 x1 + 2 x2 " A.
x1,x2"A
1, 2 " R
1 + 2 = 1
(1)
A " Mat44
ł łł
a11 a12 . . . a14 ł 1 -1 2 1 łł
ł
a21 a22 . . . a24 śł ł 1 -2 -1 2 śł
ł śł
ł śł
ł śł
= ł śł .
ł śł
ł -1 5 3
ł
3
ł ł
-2 2 3 -4
a41 a42 . . . a44
r r
r


1 -1

M2 = = -1 = 0

-2

1
2 R(A) 4 = min{ , }.
A
ł łł
1 0 0 0
ł śł
1 -1 -3 1
ł śł
A a" ł śł .
ł ł
3 2 -1 0
-2 0 7 -2
ł łł
1 0 0 0
ł śł
0 -1 -3 1
ł śł
A a" ł śł
ł ł
0 2 -1 0
0 0 7 -2
ł łł
1 0 0 0
ł śł
0 -1 -3 1
ł śł
A a" ł śł
ł ł
0 0 -7 2
0 0 7 -2
ł łł
1 0 0 0
ł śł
0 -1 -3 1
ł śł
A a" ł śł
ł ł
0 0 -7 2
0 0 0 0
ł łł
1 0 0 0
ł śł
0 -1 0 0
ł śł
A a" ł śł
ł ł
0 0 -7 2
0 0 0 0
ł łł
1 0 0 0
ł śł
0 1 0 0
ł śł
A a" ł śł
ł ł
0 0 1 0
0 0 0 0
R(A) = 3
ńł
ł - 2y + z + t = 1
x
ł
(1) x - 2y + z - t = -1
ł
ół
x - 2y + z + 5t = 5
(1)
ł łł
1 -2 1 1 1
ł śł
[A|B] = 1 -2 1 -1 -1 ł
ł
1 -2 1 5 5
ł łł
1 -2 1 1 1
ł śł
a" 0 0 0 -2 -2 ł
ł
0 0 0 4 4
ł łł

1 -2 1 1 1
1 -2 1 1 1 1 -2 1 0 0
ł śł
[A|B] a" 0 0 0 -2 -2 a" a" .
ł ł
0 0 0 1 1 0 0 0 1 1
0 0 0 0 0
(2)

x - 2y + z = 0
.
t = 1
(2) (1)
- = 2
z


1 0

t = 1 = 0


0 1
x = ą, y = , ą,  " R.
ńł
x = ą
ł
ł
ł
ł
y = 
ł
z = 2ą - 
ł
ł
ół
t = 1, ą,  " R.
ńł
ł - 2y + z = 3
x
ł
2x - 4y + 2z = 5
ł
ół
x - 6y + 3z = 9
ł łł ł łł
1 -2 1 3 1 -2 1 3
ł śł ł śł
[A|B] = 2 -4 2 5 a" 0 0 0 -1 ł
ł ł ł
1 -6 3 9 1 -6 3 9

=
ńł
ł
x + y + 2z = 0
ł
ł
ł
ł
ł 2x + 3z = 1
ł
2y + z = -1
ł
ł
ł
x
ł - y + z = 1
ł
ł
ół
2x + 4y + 5z = -1
ł łł ł łł
1 1 2 0 1 1 2 0
ł śł ł śł
ł 2 0 3 1 śł ł 2 0 3 1 śł
ł śł ł śł
ł śł ł śł
[A|B] = 0 2 1 -1 a" 0 2 1 -1 a"
ł śł ł śł
ł śł ł śł
1
ł -1 1 1 0
ł ł -2 -1 1
ł
2 4 5 -1 0 4 2 -2
ł łł ł łł

1 1 2 0 1 1 2 0
1 1 2 0
ł śł ł śł
ł 2 0 3 1 a" 0 -2 -1 1 a" a"
ł ł ł
0 2 1 -1
0 2 1 -1 0 2 1 -1

2 2 4 0 2 0 3 1
a"
0 2 1 -1 0 2 1 -1


2 0

x y =

0 2
4 = 0 z = ą ą " R

ńł
1 3
ł x = - ą,
ł
2 2
1
y = -1 - ą,
2 2
ł
ół
z = ą, ą " R.
R2 P = (xP , yP ) Q = (xQ, yQ)
R2
d : R2 [0, ")

.
df
(P, Q) = ((xP , yP ), (xQ, yQ)) d(P, Q) = (xP - xQ)2 + (yP - yQ)2
P, Q, R " R2
d(P, Q) = 0 ! P = Q
d(P, Q) = d(Q, P )
d(P, Q) d(P, R) + d(R, Q)
R2
d R2
P0 = (x0, y0) " R2 r
P0 r
K0(P0, r) = {P = (x, y) " R2 : d(P0, P ) < r}.
P0 r
K-(P0, r) = {P " R2 : d(P, P0) r}.
A " R2 K0(P0, r)
A " K0(P0, r)
A " R2
P0 " R2 A
K0(P0, r)
K0(P0, r) " A A
A0 Int(A) A
A R2
A A A0 = A
a) R2
b) R2 I0 = (a, b) (c, d)
c) "
d) R2
UP P0 " R
0
P0 UP = K0(P0, r)
0
SP SP = UP \ {P0}.
0 0 0
P0 " R2 A " R2
P0 A
A R2 R2
A R2 A = R2 \ A R2
(Pn) Pn = (xn, yn) n " N
P = (x, y)

d((xn, yn), (x, y)) < .
>0 n n0
n0"N
limn" Pn = P
Pn = P limn" Pn = P
P P
lim Pn = P ! lim xn = x '" lim yn = y.
n" n" n"
A " R2 A
Ad
A " R2 A R2
A-

P " A- ! [n" Pn = P ! P " A-].
lim
(Pn)"A
A R2
"A = A- \ A0.
A = K0(P0, r) *" {P1} P1 d(P1, P ) >
r + 1 K-(P0, r)
A
{P " R2 : d(P, P0) = r}.
P1 A A
A
Rn n = 1, 2, . . .
d : Rn Rn [0, ")

df
n
(x, y) d(x, y) = |xi - yi|2,
k=1
x = (x1, x2, . . . , xn), y = (y1, y2, . . . , yn)
Rn R R2
f : Df R " = Df " R2

f : Df R
.
P = (x, y) f(P ) = f(x, y)
f f 2
a) f(x, y) = x2 + y2 (x, y) " R2 f
Df = R2
z = x2 + y2
"
b) f(x, y) = 1 - x2 - y2 (x, y) " Df
Df = {(x, y) " R2 : x2 + y2 1} = K-((0, 0), 1).
"
z = 1 - x2 - y2 z 0
ln (x2+y2-1)
"
c) f(x, y) = f
4-x2-y2
Df = {(x, y) " R2 : 1 < x2 + y2 < 4}.
f
lim f(x, y) = +", lim f(x, y) = -".
x2+y24- x2+y21+
f : Df R P0 Df Df " R2
f
g " R# (Pn)n"N " SP )" Df
0
limn" Pn = P0 limn" f(Pn) = g.
f : Df R Df " R2 P0 " Df
P0 Df f
P0
P0 " Df P0
f P0 (Pn)n"N " Df
limn" Pn = P0 limn" f(Pn) = f(P0).
R2
f : Df R Df " R2 A " Df
f A
gć%f f : Df R Df " R2
g : Dg R f(Df) " Dg Df
f : Df R Df R2
1) Df
2) (0, 0) " Df f(0, 0) = max{f(P ) :
P " Df} (1, 1) " Df f(1, 1) = min{f(P ) : P " Df}
n
n 3 A " Rn
f
f : Df R Df " R2 P0 = (x0, y0)
Df = [ą, ]
a
f(x0 + ąt, y0 + t) - f(x0, y0)
lim ,
t0
t
f (x0, y0)
v
"f
(x0, y0)
"
v
f
(x0, y0)

x = x0 + ąt,
(l)
y = y0 + t, t " R,
Ą OY
f (t) t
t0 = 0
"f
(x0, y0)
"
v

v
f : UP R P0 = (x0, y0)
0
"f
f (x0, y0)
"x
"f
x vx = [1, 0]

"vv

"f "f
(x0, y0) = (x0, y0) =
"x "vx

f(x0 + "x, y0) - f(x0, y0)
lim .
"x0
"x
"f
f (x0, y0)
"y
"f
y vy = [0, 1]

"vy

"f "f
(x0, y0) = (x0, y0) =
"y "vy

f(x0, y0 + "y) - f(x0, y0)
lim .
"y0
"y
n n 3
0
f : Ux R x0 = (x0, . . . x0 , x0, x0 , . . . , x0)
1 i-1 i i+1 n
"f
(x0, . . . x0, x0 , . . . , x0) =
"xi 1 i i+1 n
lim
"xi0
f(x0, . . . , x0 , x0 + "xi, x0 , . . . , x0) - f(x0, . . . , x0 , x0, x0 , . . . , x0)
1 i-1 i i+1 n 1 i-1 i i+1 n
.
"xi
f : Ux0 R Ux0 " R2
f x0
A, B " R
f(x0 + "x1, x0 + "x2) - f(x0, x0) = A"x1 + B"x2 + ("x1, "x2),
1 2 1 2
 : U(0,0) R
ą) (0, 0) = 0
("x1,"x2)
) lim("x ,"x2)(0,0) " = 0
1
"2x1+"2x2
a) f x0
"f "f "f
x0 A = (x0)
"x "y "x
"f
B = (x0)
"y
b) f x0
f x0
f (x0, y0)
"f "f
df
df(x0, y0) = (x0, y0)dx + (x0, y0)dy
"x "y
f (x0, y0)
f
"f
x0
"x
"2f
(x0) x0
ptx2
"f "f
"2f (x0 + "x, y0) - (x0, y0)
"x "x
(x0, y0) = lim .
"x0
"x2 "x
"2f "2f "2f
(x0, y0) (x0, y0) (x0, y0)
"x"y "y"x "y2
f
"3f "3f "3f "3f
(x0, y0), (x0, y0), (x0, y0), (x0, y0),
"x3 "x"y2 "y2"x "x2"y
"3f "3f
(x0, y0), (x0, y0).
"y"x2 "y3
4 4
"2f "2f
"x"y "y"x
(x0, y0)
f (x0, y0)
"2f "2f "2f
df
d2f(x0, y0) = (x0, y0)dx2 + 2 (x0, y0)dxdy + (x0, y0)dy2.
"x2 "x"y "y2
m f (x0, y0)
m f

m

m "mf
df
dmf(x0, y0) = (x0, y0)dxkdym-k.
k "xk"ym-k
k=0
f(x, y) = x ln (1 + x2 + y2) Df = R2
"f 1 2x2
(x, y) = ln (1 + x2 + y2) + x 2x = ln (1 + x2 + y2) + ,
"x 1 + x2 + y2 1 + x2 + y2
"f 2y 2xy
(x, y) = x = .
"y 1 + x2 + y2 1 + x2 + y2
f (x, y)

2x2 2xy
df(x, y) = ln (1 + x2 + y2) + dx + dy
1 + x2 + y2 1 + x2 + y2
"2f 2x 2y(1 + x2 + y2) - 2xy 2x
(x, y) = + =
"x2 1 + x2 + y2 (1 + x2 + y2)2
2x 2y(1 - x2 + y2)
+ .
1 + x2 + y2 (1 + x2 + y2)2
"2f "2f 2y 4x2y
(x, y) = (x, y) = - .
"x"y "y"x 1 + x2 + y2 (1 + x2 + y2)
"2f 2x 4xy2
(x, y) = - .
"y2 1 + x2 + y2 (1 + x2 + y2)
f (x0, y0) = (1, 0)
d2f(1, 0) = 1 dx2 + 2 1 dxdy + 1 dy2.
n n 3
0
f : Ux R
0
Ux " Rn x0 = (x0, . . . , x0)
1 n
n

"f
df(x0) = (x0)dxi.
"xi
i=1
f x0
n n

"2f "2f
d2f(x0) = (x0) + 2 (x0)dxidxj.
"x2 "xi"yj
i
i=1
i,j=1,(i =j)
ł łł
"2f "2f "2f "2f
(x0) (x0) . . . (x0) (x0)
"x2 "x1"x2 "x1"xn-1 "x1"xn
1
ł śł
"2f "2f "2f "2f
ł śł
(x0) (x0) . . . (x0) (x0)
ł śł
"x2"x1 "x2 "x2"xn-1 "x2"xn
2
ł śł
ł śł
A = ł śł
ł śł
ł śł
"2f "2f "2f "2f
ł śł
(x0) (x0) . . . (x0) (x0)
"xn-1"x1 "xn-1"x2 "x2 "xn-1"xn
ł ł
n-1
"xn"x1 "2f "2f "2f
x0) (x0) . . . (x0) (x0)
( "xn"x2 "xn"xn-1 "x2
n
n n 3
0
f : U(x ,y0) R
f (x0, y0)
0 0
S(x ,y0) " U(x ,y0)
ł ł

ł
f(x, y) < f(x0, y0) ł f(x, y) > f(x0, y0)ł .
łł
(x,y)"S(x0 (x,y)"S(x0
,y0) ,y0)
f : U(x0
,y0)
R (x0, y0)
"f "f
(x0, y0) = (x0, y0) = 0.
"x "y
f(x, y) = x ln (1 + x2 + y2)
"f 1 2x2
(x, y) = ln (1 + x2 + y2) + x 2x = ln (1 + x2 + y2) + ,
"x 1 + x2 + y2 1 + x2 + y2
"f 2y 2xy
(x, y) = x = .
"y 1 + x2 + y2 1 + x2 + y2
(x0, y0) = (0, 0)
f(x, 0) = x ln (1 + x2) < 0 x < 0 f(x, 0) > 0
x > 0
n
F : Rn R
n n
df
(x1, . . . , xn) F (x1, . . . , xn) = aijxixj
i=1 j=1
aij " R '" aij = aji, i, j " {1, . . . , n}.
F (x) = F (x1, . . . , xn) = xT " A " x,
ł łł
x1

ł śł
ł śł
x = , xT = x1 . . . xn
ł ł
xn
ł łł
a11 . . . a1n
ł śł
ł śł
A =
ł ł
an1 . . . ann
f : U(x0 R
,y0)
U(x0 " R2
,y0)
ł łł
"2f "2f
(x0, y0) (x0, y0)
"x2 "x"y
ł ł
A = .
"2f "2f
(x0, y0) (x0, y0)
"y"x "y2
f : U(x0 R
,y0,z0)
U(x0 " R3
,y0,z0)
ł łł
"2f "2f "2f
(x0, y0, z0) (x0, y0, z0) (x0, y0, z0)
"x2 "x"y "x"z
ł śł
"2f "2f "2f
ł śł
A = (x0, y0, z0) (x0, y0, z0) (x0, y0, z0) .
ł ł
"y"x "y2 "y"z
"2f "2f "2f
(x0, y0, z0) (x0, y0, z0) (x0, y0, z0)
"z"x "z"y "z2
F
ł ł

ł
F (x) > 0 F (x) < 0łł .
x =Ś x =Ś
F

F (x) 0 '" F (x) > 0
x"Rn x =Ś
ł ł

ł
F (x) 0 '" F (x) < 0.łł
x"Rn x =Ś
F

F (x) F (y) < 0.
x =Ś =y
A " Matnn
ł łł
a11| a12| . . . a1r| . . . a1n-1 a1n
ł
ł a21 a22 . . . a2r| . . . a2n-1 a2n śł
śł
ł śł
ł śł
ł śł
ł śł
A =
ł
ar1 ar2 . . . arr| . . . arn-1 arn śł
ł śł
ł śł
ł śł
ł ł
an1 an2 . . . anr . . . ann-1 ann



a11 . . . a1r



a11 112


M1 = |a11|, M2 = , . . . Mr = , . . . ,


a21 a22


ar1 . . . arr
Mn = det(A),
A
1. F F (x) = xT " A " x
ł ł

ł
Mi > 0 (-1)iMi > 0łł .
i"{1,...,n} i"{1,...,n}
2. F

Mi > 0 '" Mn = 0
i"{1,...,n-1}
ł ł

ł
(-1)iMi > 0 '" Mn = 0łł .
i"{1,...,n-1}
F 1. 2.
0
x0 = (x0, . . . , x0) f : Ux R
1 n
0 0
Ux " Rn f Ux
d2f f x0
f x0
d2f(x0) x0
d2f(x0)
x2 y2
f(x, y) = + a, b > 0
a2 b2
"f "f 2y
2x
= , =
"x a2 "y b2

"f
= 0
"x
! x = y = 0.
"f
= 0
"y
(x0, y0) = (0, 0)
"2f 2 "2f "2f 2
= , = 0, = . A
"x2 a2 "x"y "y2 b2

2
0
a2
(0, 0) A = .
2
0
b2
2 4
M1 = > 0, M2 = > 0
a2 a2b2
(0, 0) f(0, 0) = 0
x2 y2
f(x, y) = - a, b > 0
a2 b2
"f 2x "f
= = -2y (0, 0)
"x a2 "y b2
"2f 2 "2f "2f 2
= = 0 = - A
"x2 a2 "x"y "y2 b2

2
0
2
a2
(0, 0) A = M1 = > 0
2
a2
0 -
b2
4
M2 = - < 0
a2b2
"f "f
f(x, y) = x2 + y4 = 2x = 4x3
"x "y
(0, 0)
"2f "f "2f
(0, 0) = 2 (0, 0) = 0 = 0
"x2 "y "x"y

2 0
(0, 0)
0 0
M1 = 2 > 0 M2 = 0
f(0, 0) - f(x, y) = -(x2 + y4) < 0 (x, y) = (0, 0) (0, 0)

f
(0, 0)
n
1
f(x1, . . . , xn) = (xi + )
i=1
xi
"f 1 "f
= 1 - i = 1, . . . , n = 0, i = 1, . . . , n
"xi x2 "xi
i
2n P = (1, 1, . . . , 1)
Q = (-1, -1, . . . , -1) -1
2n - 2 1 -1
"2f 2 "2f
= i = 1, . . . , n = 0 i = j i, j =

"x2 x3 "xixj
i i
1, . . . , n
P
ł łł
1 0 . . . 0 0
ł śł
ł śł
0 1 . . . 0 0
ł śł
ł śł
A = ł śł .
ł śł
ł śł
0 0 . . . 1 0
ł ł
0 0 . . . 0 1
Mi = 1 > 0 i = 1, . . . , n
P f(P ) = 2
Q
ł łł
-1 0 . . . 0 0
ł śł
ł -1 . . . 0 0
śł
0
ł śł
ł śł
A = ł śł .
ł śł
ł śł
0 0 . . . -1 0
ł ł
0 0 . . . 0 -1
(-1)iMi = 1 > 0 i = 1, . . . , n
Q f(Q) = -2
2n-2
f : Df R Df " Rn Df f
f
Df
f
Df
"Df Df
A Rn A Rn
f
Int(Df)
f
Df
"Df Df
n - 1, n - 2, . . . , 1, 0
A.
"Df
Df
f(x, y) =
sin x + sin y - sin (x + y) Df = {(x, y) " R2 : x + y 2Ą '" x 0 '" y 0}
"f "f
= cos x - cos (x + y) = cos y - cos (x + y)
"x "y

cos x - cos (x + y) = 0 cos x = cos y
! !
cos y - cos (x + y) = 0 cos y = cos (x + y)
(x = y + 2kĄ (" x = -y + 2kĄ) '" (cos y = cos (x + y)).
x = y cos x = cos 2x
2
Df (2Ą, Ą)
3 3
" " "
"
2 2 4 3 3 3 3
f(2Ą, Ą) = sin Ą - sin Ą = + + = 3
3 3 3 3 2 2 2 2
A = {(x, 0) : 0 x 2Ą} f(x, 0) = sin x - sin x = 0
B = {(0, y) : 0 y 2Ą} f(0, y) = 0
C = {(x, 2Ą - x) : 0 x 2Ą} f(x, 2Ą - x) = sin x +
sin (2Ą - x) - sin 2Ą = 0
2
3
" Df (2Ą, 3Ą)
3
3 0
2
Df
f f(x, y) = xy(1 - x - y) f(x, y) =
xy - x2y - xy2
"f "f
(x, y) = y - 2xy - y2, (x, y) = x - x2 - 2xy.
"x "y

"f
(x, y) = 0
y(1 - 2x - y) = 0
"x
!
"f
(x, y) = 0 x(1 - x - 2y) = 0
"y
x = 0 y = 0 y = 1 (0.0), (0.1)
y = 0 x = 0 x = 1 (1, 0)
2xy = 2xy y - y2 = x - x2 y - x = y2 - x2
y - x = y2 - x2 ! (y - x)(1 - x - y) = 0.
1
x = y x2 - 3x2 = 0 (1, )
3 3
"2f "2f "2f
(x, y) = -2y, = -2x, (x, y) = 1 - 2x - 2y.
"x2 "y2 "x"y

0 1
(0, 0).
1 0

0 -1
(1, 0).
-1 -2

-2 -1
(0, 1).
-1 0

1 1
-2 -1
3 3
( , ).
-1 -2
3 3
3 3
1
(1, )
3 3
1 1
f(1, ) =
3 3 27
(0, 0)
(1, 0) (0, 1) f
(1.0)
f x - y = 1
= [1, 1]
v
y = x - 1 (x) = f(x, x - 1) = -2x2(x - 1) x > 1
x < 1
(0, 1) f y = x
R
R
A-1
(1)


Wyszukiwarka